Equivalent static wind loads on canopies of regular railway stations

Abstract

Wind-induced response, spectrums of the modal generalized force, and equivalent static wind loads (ESWLs) of railway station canopies with single-span and three-span frame are investigated. The results show that the first mode dominates horizontal displacements and frame column stresses, and the second mode dominates vertical displacements and frame beam stresses of the canopy frames. The unfavorable wind directions are determined for the center, near-center and end frames. Based on wind tunnel test results, parameters of simplified mean wind dynamic pressure coefficients and the generalized modal force spectrum formula for the first and second modes are proposed for different canopy span, opening widths and building height ratios of the station building to the canopy. Combining above-mentioned wind-induced response characteristics with the analysis method of universal ESWLs, the ESWLs are derived as the superposition of the peak inertia forces of the two dominating modes, and all nodal displacements and all member stresses under this unique ESWLs are equivalent to the actual dynamic peak responses. The numerical example verifies that all nodal displacements and member stresses calculated by the proposed semi-analytical formula simultaneously agree well with the actual dynamic peak response.